Method of and machine for making molds



Jan 159 1924. 1,480,75

' H. L. DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS b. 15. 1922 10 Sheets-Sheet 1 Jan. 15:, 1924.

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H. I... DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS Filed Feb. 15, 1922 10 Sheets-Sheet 3 Jane 15, 1.9240

H. L. DEMMLER msww METHOD OF AND MACHINE FOR MAKING MOLDS Filed Feb. 15. 1.922

10 Sheets-Sheet 4 Jan 15 H. L. DEMMLER METHOD OF AND MACHINE FOR MAKlNG MOLDS Filed Feb. 15. 1922 1O Sheets-Sheet 5 Jam. l5, 1924a BAMWEG H. 1.. DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS Filed Feb. 15. 1922 10 Sheets-Sheet 6 Jan. 15 1924.

H. L. DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS 1o Sheets-Shet 7 Filed Feb. 15 1.922

Jam T15 1924., TLA-fiQjSQ H. L. DEMMLEIR METHOD OF AND MACHINE FOR MAKlNG MOLDS Filed Feb. 15 1.922 10 Sheets-Sheet 8 Jam 15, 11924 L48fi5 H. L. DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS Filed Feb. 15. 1922 10 sheets-Sheec 9 xid Jan. 15, 1924. 1,48%750 H. L. DEMMLER METHOD OF AND MACHINE FOR MAKING MOLDS Filed Feb. 15. 1922 10 Sheets-Sheet 10 if z- Patented Jan. 15, 1924.

UNITED STATES PATENT OFFICE.

HENRY L. DEMMLER, OEKEWANEE, ILLINOIS.

METHOD OF AND MACHINE FOR MAKING HOLDS.

To all whom it may concern:

Be it known that I, HENRY L. DEMMLER, a citizen of the United States, and resident of Kewanee, in the county of Henry and State of Illinois, have invented a certain new Method of and Machine for Making Molds, of which the following is a full, clear, concise, and exact description, reference being bad to the accompanying drawings, forming a part of this specification.

The present invention relates to molding machines and methods and particularly to those by which the mold is formed pneumatically. The principal object of the invention is the provision of a machine and method for pneumatically forming green sand molds and especially such molds having complex form and contour. Other obj ects of the inventionare concerned with the provision of a machine for doing the work stated, which shall be automatic and eflicient in operation and which as a whole and in its parts is best adapted to perform its functions. The present application is in part a continuation of applicants applications, Serialv No. 492.033 filed August 13, 1921, Serial No. 492.810 filed August 16, 1921. and Serial No. 498,650 filed September 6, 1921.

In the drawings,-

Figure 1 is a front elevation of a machine embodying the invention.

Figure 2 is a side elevation of the machine but with an arm which carries certain of the parts swung to operative position.

Figure 3 is a vertical section on the line 3-3 in Figure 1, but with the arm in operative position.

Figure 4 is a section on the line 44 in Figure 1.

Figure 5 is a broken section on the line 55 in Figure 2.

Figure 6 is a broken section on the line 66'in Figure 2. I

Figure 7 is an elevation of the swinging arm carried by the main frame.

Figure 8 is a vertical section thereof.

Figure 9 is an enlarged sectional view on the line 99 in Figure 8.

Figure 10 is a section on the line 10-10 in Figure 8.

Figure 11 is a view similar to Figure 10 but with the parts shown in different operative position.

Figure 12 is an elevation ofa flask with a mold formed therein.

Figure 13 is a broken plan view looking at the bottom of Figure 8. i

Figure 14 is a brokenv vertical section through the pedestal mentioned.

Figure 15 is an enlarged sectional view of a mold vent.

The detailedoonstruction and operation of the machine may be more readily understood if the preferred cycle of operations be stated first. In preparing to form a mold a flask is secured against the lower face of a flask plate or closure, constituting a selectively vented mold form, carried by a swinging arm which at this stage is swun back out of operative position. A san container is then charged with sand, following which the container is jolted to compact the sand. Usually a considerable quantity of sand is in the container prior to the charging of additional sand, in which event the container will be jolted both before and after receiving the new charge of sand. I

After the sand has been compacted in the container the arm carrying the ,flask is swung into position so that the flask immediately overlies the sand container. The

sand container and flask are then pneumati- 'cally clamped together, following which an air blast is admitted below the sand in the container and the sand is forced up into the flask to form the mold. The flask is then unclamped from the sand container and the arm carrying the flask is swung out until the flask is positioned over apedestal. This pedestal comprises a cylinder with differential pistons, one of which rises to contact with the under side of the flask. The other piston rises to pierce and vent the mold and after it has descended the first piston smoothly lowers the'mold from its supporting arm. The mold is then ready for use. The machine comprises a base 1 supporting a frame which may be suitably formed by four up-right angle irons 2 rigidly connected by suitable braces 3. At one side of the front of the frame is a stanchion 4 on which oscillates an elongated heavyrsleeve 5 formed with a projecting arm 6. The machine illustrated is adapted to the for mation of molds for the casting of internal combustion engine pistons and parts of the mechanism carried by the arm 6 are designed with this particular purpose in view. At a single operation the machine illustrated produces What in ordinary practice would require the ramming of the drag of the flaskandthe independent formation ofseparate cores for the casting of four separate pistons. The present machine forms in the drag a homogeneous body of sand having four upstanding projecting portions over which the molds in the cope will be placed. To this end the arm 6 carries a housing 7 to the under side of which is bolted or secured a supplementary housing 8. The supplementary housing contains separable mold boxes 9 for forming the projecting portions, or cores, of molded sand. Against the bottom plate 10 of the supplementary housing 8 is bolted or otherwise secured a flask plate 11 against the under face of which the flask is to be secured. The bottom plate 10 of the supplementary housing and the flask plate 11 are 'formed with large openings 12 registering with the separable mold boxes within the supplementary housing. Surrounding these openings in the flask plate 11 a plurality of plates or cups 13 are set into. the plate. The faces of the plates or cups 13 are flush with the lower surface of the flask plate 11 and are formed with a plurality of minute perforations 14 opening into recesses 15 in .the flask plate, which communicate freely with the atmosphere. These perforations 14 are preferably formed as illustrated in Figure 15 so that if during the formation of a mold a grain of sand happens to get into one of the perforations it will have an enlarged and free path for instant removal with the air blast through the recesses 15 in the plate 11. The supplementary housing 8 carries a cross-plate 1.6 supporting the tops 17 which overlie the separable mold boxes 9. The c lindrical portion of these boxes is made up of two laterally separable parts 9 which slide on the bottom plate 10 of the supplementary housing 8, and perforated plates or cups 13 similar to those in the flask plate are set into the mold boxes so as to be flush with their internal surfaces and communicate with the atmosphere. The halves of the boxes are conveniently separated by means of a handle 18 oscillating on a standard 19 and having pivoted to its opposite ends links 20 pivoted at their other ends to the respective halves 9 of two of the boxes. These halves 9 of the two mold boxes are connected by pins 21 with the halves 9 of the other two boxes so that upon operation of the handle 18 allfour boxes will be opened or closed.

Two members 22 are slidable on guide pins 23 fixedly secured in the housing 7 and each of these members supports a pair of magnets 24 having pole pieces 25 embracing one of the separable boxes 9-9. The lower ends of the pole pieces 25 are beveled to correspond with beveled surfaces 26 on the exterior of the boxes and when the magnets are energi r d by a. suitable switch controlling a circuit not shown, the pole pieces 25 with their, magnets and supporting member 22 are pulled down so that the beveled surfaces are in contact and securely hold the boxes 9 in closed position. Each of two sliding bars 27 bears downwardly against a leaf spring 28 which at its free end carries a pin 29 engaging a shoulder 30 on one of the members 22. The upper ends of these bars 27 project beyond the housing 7 and are formed with cam surfaces 31 which are engaged by another part of the machine when the arm 6 is swung into operative position,

thus insuring that the pole pieces 25 are fully depressed to hold the mold boxes 9 closed. When the magnets 24 are deenergized, the meinbers 22 carrying the magnets are pulled upwardly by springs The with downwardly projecting pins 33 adapted to enter positioning holes 34 in the flask 35. The flask is clamped in position against the under face of the flask plate by magnets 36 which when suitably energized act through their pole pieces 37 to hold the flask securely against the flask plate. The flask 35 is formed with a plurality of holes 72 in its bottom through which sand is to be blown upwardly.

Referring to the main frame of the machine, a cylinder 38 is secured to the base at the front of the frame and slidable therein is a second open mouthed cylinder 39. Suitable packing 40 is provided between these two cylinders so that their fit is airwith packing 41 in its upper flanged face 42.

'VVhen a mold is being blown the flask is clamped against the flanged face 42 of the inner cylinder 39 and the packing in this face insures an air-tight union between the cylinder and flask. The cylinder constitutes a sand container, at the lower end of which an airdilast is to be admitted to force the sand upwardly out of the container and into the flask. For this purpose the outer cylinder 38 is provided with a controlling valve mechanism 43 by which air pressure may be admitted to the container, the air inlet being protected by a baflie 44 formed in the inner cylinder 39 so that the air will be forced to pass to the bottom of the container and thence directly upwardly.

An initial supply of sand may be shoveled into the sand container and after each formation of a mold a considerable supply of sand will still remain in the container. It is desirable, however, to furnish the container with an additional'charge of sand and level it ofl preceding each operation. For this purpose a stationary hopper 46 is mounted in the frame and it may be supplied with sand by a conveyor or otherwise. Immediately below the hopper is a charger 47 movable forwardly and backwardly on supportflask'plate 11 is provided at opposite sides ing rollers 48 journaled on the frame. Rearwardly of the charger a cylinder 49 is fixedly supported by a cross-member 50 secured to the frame and the pistonrod 51 of this cylinder is secured at its front end to a transverse partition 52 of the charger. The bottom plate 53 of the charger is slidable with relation to the sides of the charger and is provided with a projection 54 adapted to strike a stop as the carrier moves forwardly. The top plate 55 of the charger is also slidable in order to permit a charge of sand to flow from the hopper 46 into the sand compartment 56 of-the charger. After the compartment has been filled, pressure applied behind the piston of the cylinder will carry the entirecharger forward. lVhen the front edge of the bottom plate 53 reaches the near edge of the sand container the projection thereon strikes its stop and limits its further movement, while the other parts of the charger continue to move forward until the compartment 56 is above the container and the charge of sand has been deposited therein. The air pressure behind the charger piston is then out off and air admitted to the other side of the piston, whereupon the charger is retracted, during which movement a scraper 57 levels off the sand in the container. Any excess sand will flow down the chute 58.

Fixedly supported at the top of the frame is a piston 59 whose movable cylinder 60 carries a cross-head 61. Depending from the ends of the cross-head 61 are rods 62 slidably engaging the upper ends of bars 63, the rods 62 being formed with heads 64 to limit relative movement between the rods 62 and bars 63. The lower ends of the bars 63 are provided on both front and back faces with pins 65 which engage under arms 66 projecting from the inner slidable cylinder 39 of the sand container. The piston 59 and cylinder 60 are provided with a control valve mechanism of any usual construction (such for instance as illustrated in Hewlett and Dcmmler United States Patent No. 1.086824, Feb. 10, 1914) by which, so long as the air line is open, air will be rapidly and alternately admitted to and exhausted from the cylinder. The consequent rapid rise and fall of the cylinder 60 and crosshead 61 causes a corresponding rise and fall of the sliding cylinder 39 of the sand c011- tainer. This action thoroughly jolts and compacts the sand in the container so that when subsequently the air blast is admitted into the container the upwardly flowing air does not channel and cut through the sand but in large measure exerts its pressure upwardly against the compact mass of sand. Actual practice demonstrates that when the sand is compacted to offer greater resistance as albody to the air blast the sand will be more quickly conveyed and more closely and solidly packed into all parts and recesses "sary to clamp the flask against the sand container. For this purpose a cylinder 67 is fixedly supported by the frame, preferably by bolting or otherwise securing it to the front upright members of the frame. The piston 68 operable in the cylinder 67 has secured to it a cross-head69 formed with elongated slots 70 engaging pins 71 project ing from the two slidable bars 63. lVhen air is admitted below the piston 68 the crosshead 69 pulls the bars 63 upwardly, and they in turn raise the sliding cylinder 39 of the sand container and securely clamp it against the bottom of the flask 35. During the clamping operation relative movement of the bars 63 with relation to the rods 62 is permitted by their slidable connection, while on the other hand it will be noted that movement of the bars 63 with relation to the cross-head 69 during the jolting of the sand container is permitted by the pin and slot connection between the bars and the crosshead.

As soon as the sand container and flask have been clamped together'the air blast is admitted to the sand container, forcing the sand upwardly through the holes 72 in the bottom of the flask 35 and forming the mold. It will be appreciated that the flask plate 11 and the mold boxes 9 with their tops 17 constitute a closure for the flask and, together with the flask, constitute a mold form. The members of which the mold form is composed and the arrangement and shape of the members may vary, form of the mold to be produced. In any case, however, the mold form will be provided' with vents to the atmosphere and these vents are selectively located relative to the shape and contour of the mold form, so that the blast of air will flow along desired paths andescape freely at desired points, thus conveying and solidly packing the retained sand into all parts of the mold form and doing so almost instantly. The best tained by forming the vents as openings in the molding surface, and this is preferably accomplished by placing the perforated plates or cups 13 as parts of the surface against which the sand is to be molded. Venting the mold form in this Way produces a superior mold Whether the sand be blasted upwardly or downwardly into the form, but additional important results and efliciency of course, with the results are ob-- are obtained by blowing the sand upwardly into the form. In the formation of any mold it is found that this produces a more accurate and solidly packed mold, probably due to the fact that the sand is forcefully carried into all parts of the mold form rather than merely being allowed to fall into the form in the presence of compressed air.

But furthermore, it provides for the formation of intricate molds consisting of one homogeneous mass of sand and eliminates any necessity of turning the mold over. If in addition to venting the mold form as stated, or blasting the sand upwardly into the form, or both, the sand be compacted in the container before subjecting it to the air blast, the best results in operation and product will be obtained. I prefer a machine in which the mold form is properly vented and in which, after the sand has been compacted, the air blast forces the sand upwardly into the form. I

The mold will be formed almost instantly, after which the air blast is discontinued and the pressure in the clamping cylinder 67 exhausted. A vent 45 below the cylinder 39 permits its instant descent. The arm 6 is then swung outwardly until the flask 35..is positioned over the pedestal illustrated in the right lower corner of Figure 1. This pedestal comprises a fixed cylinder 7 3 in which slides a hollow piston 74 provided at its lower end with a head 75 and havingat its upper end a projecting flange 76 carrying upwardly extending supports 77. This pis' ton is caused to rise by the admission of air through the pipe 119 and is allowed to fall by exhausting the confined air through the pipe 119, the inlet and exhaust of air being controlled by a suitable hand valve. A second piston 78 is slidable within the first piston 74 and the two are formed with co-operating shoulders 79 so that when the outer piston rises the inner one also is raised. The inner'piston has a head 80 provided with plungers 81' adaptedto extend'through the bottom of the flask and pierce the molded sand to vent it. After the pistons have been raised until the supports 77 contact with the bottom of the flask, the inner piston is further raised to vent the mold by air admitted through a pipe 120 which extends downwardly through the inner piston and opens through the head at the bottom thereof into the space between the bottom heads of the two pistons. The confined air holding the inner piston raised relatively to the outer piston is exhausted through the pipe 120, the inlet and exhaust of air through the pipe being controlled by a suitable hand valve. 1

It is obvious that there may be considerable variation in the specific mechanism used for controlling the operations of the several parts of the machine. An efiicient and preferred mechanism, however, is illustrated in the drawingsu Power is applied to a pulley 82 secured on a shaft journaled near the top of the frame, which is geared to drive shaft 83- hearing a sprocket 84 which may be used if desired for operating a conveyor to lead sand into the hopper 46. Through a suitably controlled clutch mechanism the main shaft is geared to a second shaft 87 which is connected by reducing gears 88 to operate a cam shaft 89. In 'the preferred sequence of operations the supply of sand retained in the container will first be compacted by jolting the container. This will be accomplished by engagement of a projecting cam 90 on the cam wheel 91 with a follower 92 carried by a bell crank lever 93, which will raise a valve rod 94 against resistance of the spring 95 to open the control valve 96 which is connected by an air line 97 with the jolt cylinder 60. As previously stated, a suitable valve mechanism is included in the air line so that while the valve 96 is open pressure will be rapidly and alternately admitted to and ex hausted from the 'jolting cylinder. As soon as rotation of the cam shaft closes the jolt control valve 96, the valve rod 98 is raised to open valve 99 and admit pressure behind the piston in the charging cylinder 49., through air line 100. After the charge of sand has been deposited in the container the valve 99 is permitted to exhaust, while the valve rod 101 is raised to open the valve 102 and establish pressure through the air line ;,103 on the opposite side of the piston to retract the charger. The jolt control valve 96 is nowopened again as before to compact the sand received from the charger. As soon as this charge has been compacted, the arm 6 carrying the flask 35v is swung into position over the sand container and during this interval the handle 86 may be operated to disconnect the clutch if desired. When the arm is in position and the machine in operation, the cam 104 raisesthe rod 105 to open the valve 106 and admit pressure below the clamping piston 68 through air line 107. As soon as the flask and sand container are thus clamped together, the cam 108 operates to establish the air blast. The valve rod 109 is connectedto operate the control valve 43 which admits into the sand container a blast from the main pressure supply line 111. It may be here noted that the other control valves referred to are connected by air lines with a header 112 communicating with the main supply line 111. The control valve rod lower to fall back into inoperative position. By this means the operator may eliminate the dangerouspossibility of the air blast being admitted to the sand container when a flask is not clamped over the container. After rotation of the cam shaft.permits spring actuated closure of the control valve 43 to discontinue the air blast, continued rotation of the cam shaft permits exhaust through the valve 106 to release the clamping piston, descent of the container cylinder being hastened by vent 45. The arm 6 carrying the flask 35 is now swung outwardly to position the flask over the pedestal. A suitable valve is then operated toadmit pressure below the iston 74, whereupon the two pistons 74 and 7 8 rise until the supports 77 contact with the under side of the flask 35. The inner piston 7 8 is then raised still further to vent the mold and then by suitable valve operation is permitted to fall. All of the mold control magnets are then deenergized and by any suitable vibratin mechanism themold boxes may be freed from the mold. Thereupon the separable mold boxes 9 are opened and pressure is exhausted from below the outer piston 74, allowing the flask and mold gently to be lowered. A flask containing the completed mold is illustrated in Figure 12 and it is ready to receive thecope, ithout the necessity of separately forming cores.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. In a molding machine, the combination of a sand container having an outlet, means for securing a mold form to the container in register with the outlet, means for jolting the container, and means for supplying gaseous fluid pressure to the container to force sand into the form.

2. In a molding machine, the combination of a sand container having an outlet at its top, means for securing a mold form over' the container, means for compacting sand in the container, and means for. supplylng gaseous fluid pressure to the container to force sand upwardly into the form. a

3. In a molding machine, the combination of a sand container having an outlet at its top, means for securing a mold form over the container, means for jolting the container, and means for supplying gaseous fluid pressure to the container to force sand upwardl into the form.

4. Iii a molding machine, the combina tion of a sand container having an outlet at its top, means for securing a mold form over the container, means for compacting sand in the container, and means for supplying gaseous fluid pressure to the contalner substantially at the bottom "thereof to force sand upwardly into the form. V

v 5. In a molding machine, the combinaw tion of a sand container having an outlet at its top, means for securin a mold form over the container, means for olting the container, and means for supplying gaseous fluid pressure to the container substantially at the bottom thereof to force, sand upwardly into the form.

6. In a molding machine, the combination of a fixed cylinder having a lateral opening, a slidable cylinder fitted in the fixedcylinder and having a lateral opening adapted to register with the opening in the fixed cylinder, the slidable cylinder having a closed bottom and an outlet in its top, a bafile in the slidable cylinder across its lateral opening and terminating close to the bottom of the cylinder, means for securing a mold form over the top of the slidable cylinder, means for jolting the slidable cylinder, and means for supplying gaseous fluid pressure through said lateral openings.

7. In a molding machine, the combination of a sand container having an outlet, means for compacting sand in the container, a mold form provided with vents selectively located relative to the contour of the form for permitting escape of pressure fluid but not of sand from the form, means for securing the form to the container in register with the outlet, and means for supplying gaseous fluid pressure to the container to force sand into the form.

8. In a molding machine, the combination of a sand container having an outlet in its top, means for compacting sand in the container, a mold form provided with vents for permitting the escape of pressure fluid but not of sand from the form, means for securing the form over the container, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the form.

9. In a molding machine, the combina-' 'fiuid pressure to the container to force sand upwardly into the form.

10. In a molding-machine, the combination of a sand container having an outlet in its top, means for compacting sand in the container, a mold form provided with a plurality of apertures communicating with the atmosphere, plates secured in said apertures constituting part of the molding surface, the plates being provided with a plurality of minute openings, means for securing the form over the container, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the form.

11. In a molding machine, the combination of a sand container having an outlet in its top, means for jolting the container, a mold form provided with a plurality of apertures communicating with the atmosphere, plates secured in said apertures constituting part, of the molding surface, the plates being provided with a plurality of minute openings, means for securing the form over the container, and means for sup plying gaseous fluid pressure to the container substantially at the bottom thereof to force sand upwardly into the form.

12. In a molding machine, the combination of a sand container having an outlet in its top, a mold form provided withvents for permitting the escape of pressure fluid but not of sand from the form, means for securing the form over the container, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the form. x

13. In a molding machine, the combination of a sand container having an outlet in its top, a mold form provided with a plurality of minute openings in the molding surface communicating with the atmosphere, means for securing the form over the container and means for su )l in aseous tion of a sand container having an open top, a mold form having an apertured bottom, means for securing the form over the container, and means for supplying gaseous fluid pressure to the container to force sand upwardly'into the form.

16. :Ihjif'at, molding machine, the combina tion on sand container having an open top, a flask having an apertured bottom, a closure adapted; to overlie the flask, means for'securing the flask between the container and closure, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask.

17. In a molding machine, the combination of a. sand container having an 'open top, a flask having an apertured bottom, an apertured closure adapted to overlie the flask, a mold form disposed above the aperture in the closure, means for securing the container, flask,'closure and form together,

and means for supplying gaseousfluid pres 15. In a molding machine, the combina sure to the container to force sand upwardly into the flask and form.

18. In a molding machine, the combination of a sand container having an open top, a flask having an apertured bottom, an apertured plate adapted to overlie the flask, a laterally separable mold form disposed above the plate and registering with the aperture therein, means for securing the container, flask, plate and form together, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask and form.

19. In a molding machine, the combination of a sand container having an open top, a flask having an apertured bottom, a molding closure adapted to overlie the flask and provided with a plurality of minute openings in the molding surface communicating with theatmosphere, means for securing the flask between the container and closure, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask.

20. In a molding machine, the combination of a sand container having an open top, a flask having an apertured bottom, an apertured molding closure adapted to overlie the flask, a mold form disposed above the aperturein the closure, the closure and form being provided with a plurality of minute openings in the molding surfaces communicating with the atmosphere, means for securing the container, flask, closure and form together, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask and form, I

21. In a molding machine, the combination of a sand container having an open top, a flask having an apertured bottom, an apertured molding closure adapted to overlie .the flask, a mold form disposed above the aperture in the closure, the closure and form being provided with a plurality of apertures communicating with the atmosphere, plates secured in the last named apertures constituting part of the molding surfaces, the plates being provided with a plurality of minute openings, means for securing the container, flask, closure and form together, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask and form.

22. In a molding machine, the combination of a sand container having an open top, means for compacting sand in the container, a flask having an apertured bottom, a molding closure adapted to overlie the flask and provided with a plurality of minute openings in the molding surface communicating with the atmosphere, means for securing the flask between the container and closure, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask.

all

. 23. In a molding machine, the combination of a sand container having an open top, means for compacting sand in the container, a flask having an apertured bottom, an apertured molding closure adapted to overlie the flask, a mold form disposed above the aperture in the closure, the closure and form being provided with a plurality of minute openings in the molding surfaces communicating with the atmosphere, meansv for securing the container, flask, closure and form together, and means for supplying gaseous fluid pressure to the container to force sand upwardly into the flask and form. 24. In a molding machine, the combination of a sand container having an open top, means for compacting sand'in the container, a flask having an apertured bottom, an apertured moldin closure adapted to over- Fd form disposed above the aperture in theclosure, the closure and form being provided with a plurality of apertures communicating with the atmosphere, plates secured in the last named apertures con stituting part of the molding surfaces, the

plates being provided with a plurality of minute openings,'means for securing the container, flask, c osure and form together, and means for supplying gaseous fluid pressure I to the container to force sand upwardly into the flask and form.

25. In a molding machine, the combination of a sand container having an open top, means for jolting the container, a flask having an apertured bottom, an apertured molding closure adapted to overlie the flask, a mold form disposed above the aperture in the closure, the closure and form being provided with a plurality of. apertures communicatin with the atmosphere, plates secured in tfle last-named apertures constituting part of the molding surfaces, the plates being provided with a plurality of minute openings, means for securing the container,

- flask, closure and form together, and means for supplying gaseous fluid pressure to the container substantially at the bottom thereof to force sand upwardly into the flask and form.

26. In a moldin machinefthe combination of a vertica ly slidable container, a pneumatically operable vertically reciprocable member, a second pneumatically operable vertically reciprocable member, and

a bar connected with the container and slidably connected with, butlimited in movement relative to, each of said members.

27. In a moldin machine, the combination of a vertical y slidable container, a cross-head, pneumatically operated means for reciprocating the cross-head, a plurality of bars connected to the container and slidably connected with the'cross-head, projections limiting upward movement of the cross-head relative to the bars, asecond crosshead provided with vertical slots, pins on 'the bars engaging the slots, and pneumatically operated means for raising the second cross-head.

28. In a molding machine, the co1nbination of a vertically slidable container, :1 crosshead, pneumatically operated means for reciprocating the cross-head, a plurality of bars connected to the container and slidably connected with the cross-head, projections limiting upward movement of the cross head relative to the bars, a second cross-head provided with vertical slots, pins on the bars engaging the slots, pneumatically operated means for raising the second cross-head, and means for supplying gaseous fluid pressure to the container.

29. In a molding machine, the combination of a frame, a horizontallyswinging arm supported thereby, a flask closure carried by the arm, and means for securing a flask to the closure.

30. In a molding machine, the combination of a frame, a sand container, a horizontally swinging arm supported by the frame, a flask closure carried by the arm, means for securing a flask to the closure, and means for clampin the container to the flask when the arm is swung into operative position.

31. In a molding machine, the combinas tion of a frame, a sand container, a horizontally swinging arm supported by the frame, a flask closure carried by the arm, means for securing a flask to the closure, means for jolting the container, and means for clamping the container to the flask when the arm is swung into operative position.

32. In a molding machine, the combination of a flask cover plate, a magnet for securing a flask thereto, a separable mold form slidable on the late, means for opening and closing the orm, and magnets for securing the form in closed position.

33. In a molding machine, the combination of a support, means for suspending a flask therefrom, a cylinder disposed below the support, a piston operable therein and adapted to be raised to support and lower the flask, and a second piston slidably fitted to the first piston and provided with projections adapted to be extended through the flask. I I

34. In a molding machine, the combination of a support, means for suspending a flask therefrom, a cylinder disposed below the support, and a pair of pistons pneumatically operable in the cylinder and telescoping with each other, one piston being adapted to support and lower the flask and the other being provided with projections adapted to extend through the flask.

35. In a molding machine, the combination of a support, means for suspending a flask therefrom, a cylinder disposed below the support, a piston operable therein and adapted to .be raised to support the flask, a second piston slidablerelative to the first piston and provided With projections adapted to be extended through the flask, the pistons being formed with complementary projcctions whereby rise of the first piston raises the second piston, and pneumatic means for operating the first piston and for independently operating the second piston.

. 36 The method of molding sand in a form, comprising compacting a mass of sand and then directing an air blast against the mass to force sand into the form and permitting the escape of air through vents selectively located relative to the con-tour of the form 37. The method of molding sand in a form,

the form.

In witness whereof, I hereunto subscribe my name this 10th day of February, 1922. 25

HENRY L. DEMMLER. 

